Which of the following correctly describes Purkinje images?

Purkinje images are formed by the reflection of light off the optical surfaces of the eye, specifically the anterior and posterior surfaces of the cornea and the lens. These images are a result of light reflecting back into the eye after hitting these curved surfaces.

There are typically four Purkinje images: the first is a reflection off the front surface of the cornea, the second off the back surface of the cornea, the third off the front surface of the lens, and the fourth off the back surface of the lens. Since they are reflections rather than direct images formed by the retina or within the vitreous body, the description involving reflection off the eye's optical surfaces is the most accurate and appropriate.

The other options do not accurately describe the formation of Purkinje images. Images formed by light refraction through the retina pertain more to the perception of images within the visual pathway rather than reflections. The corneal stroma does not generate images but is rather involved in the optical clarity of the eye. Additionally, while the vitreous body is important for maintaining the shape of the eye, it is not where Purkinje images are generated. This reinforces the correctness of the answer, focusing on the optical nature of these images.